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Zhang Z, Bie X, Chen Z, Liu J, Xie Z, Li X, Xiao M, Zhang Q, Zhang Y, Yang Y, Li D. A novel variant of DNM1L expanding the clinical phenotypic spectrum: a case report and literature review. BMC Pediatr 2024; 24:104. [PMID: 38341530 PMCID: PMC10858475 DOI: 10.1186/s12887-023-04442-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 11/23/2023] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND Mitochondrial diseases are heterogeneous in terms of clinical manifestations and genetic characteristics. The dynamin 1-like gene (DNM1L) encodes dynamin-related protein 1 (DRP1), a member of the GTPases dynamin superfamily responsible for mitochondrial and peroxisomal fission. DNM1L variants can lead to mitochondrial fission dysfunction. CASE PRESENTATION Herein, we report a distinctive clinical phenotype associated with a novel variant of DNM1L and review the relevant literature. A 5-year-old girl presented with paroxysmal hemiplegia, astigmatism, and strabismus. Levocarnitine and coenzyme Q10 supplement showed good efficacy. Based on the patient's clinical data, trio whole-exome sequencing (trio-WES) and mtDNA sequencing were performed to identify the potential causative genes, and Sanger sequencing was used to validate the specific variation in the proband and her family members. The results showed a novel de novo heterozygous nonsense variant in exon 20 of the DNM1L gene, c.2161C>T, p.Gln721Ter, which is predicted to be a pathogenic variant according to the ACMG guidelines. The proband has a previously undescribed clinical manifestation, namely hemiparesis, which may be an additional feature of the growing phenotypic spectrum of DNM1L-related diseases. CONCLUSION Our findings elucidate a novel variant in DNM1L-related disease and reveal an expanding phenotypic spectrum associated with DNM1L variants. This report highlights the necessity of next generation sequencing for early diagnosis of patients, and that further clinical phenotypic and genotypic analysis may help to improve the understanding of DNM1L-related diseases.
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Affiliation(s)
- Zhenkun Zhang
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Xiaofan Bie
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Zhehui Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Jing Liu
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Zhenhua Xie
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Xian Li
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Mengjun Xiao
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Qiang Zhang
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Yaodong Zhang
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China
| | - Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
| | - Dongxiao Li
- Henan Provincial Clinical Research Center for Pediatric Diseases, Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China.
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Lhuissier C, Wagner BE, Vincent A, Garraux G, Hougrand O, Van Coster R, Benoit V, Karadurmus D, Lenaers G, Gueguen N, Chevrollier A, Maystadt I. Case report: Thirty-year progression of an EMPF1 encephalopathy due to defective mitochondrial and peroxisomal fission caused by a novel de novo heterozygous DNM1L variant. Front Neurol 2022; 13:937885. [PMID: 36212643 PMCID: PMC9538651 DOI: 10.3389/fneur.2022.937885] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
Mutations in DNM1L (DRP1), which encode a key player of mitochondrial and peroxisomal fission, have been reported in patients with the variable phenotypic spectrum, ranging from non-syndromic optic atrophy to lethal infantile encephalopathy. Here, we report a case of an adult female patient presenting with a complex neurological phenotype that associates axonal sensory neuropathy, spasticity, optic atrophy, dysarthria, dysphasia, dystonia, and ataxia, worsening with aging. Whole-exome sequencing revealed a heterozygous de novo variant in the GTPase domain of DNM1L [NM_001278464.1: c.176C>A p.(Thr59Asn)] making her the oldest patient suffering from encephalopathy due to defective mitochondrial and peroxisomal fission-1. In silico analysis suggested a protein destabilization effect of the variant Thr59Asn. Unexpectedly, Western blotting disclosed profound decrease of DNM1L expression, probably related to the degradation of DNM1L complexes. A detailed description of mitochondrial and peroxisomal anomalies in transmission electron and 3D fluorescence microscopy studies confirmed the exceptional phenotype of this patient.
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Affiliation(s)
- Charlène Lhuissier
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Unité MitoVasc, SFR ICAT, Université d'Angers, Angers, France
| | - Bart E. Wagner
- Department of Histopathology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Amy Vincent
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gaëtan Garraux
- GIGA-CRC in vivo Imaging, University of Liège, Liège, Belgium
- Department of Neurology, CHU Liège, Liège, Belgium
| | | | - Rudy Van Coster
- Division of Pediatric Neurology and Metabolism, Department of Pediatrics, Ghent University Hospital, Ghent, Belgium
| | - Valerie Benoit
- Institut de Pathologie et de Génétique, Gosselies, Belgium
| | | | - Guy Lenaers
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Unité MitoVasc, SFR ICAT, Université d'Angers, Angers, France
- Service de Neurologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Naïg Gueguen
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Unité MitoVasc, SFR ICAT, Université d'Angers, Angers, France
- Service de Biochimie et Biologie Moléculaire, CHU Angers, Angers, France
| | - Arnaud Chevrollier
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Unité MitoVasc, SFR ICAT, Université d'Angers, Angers, France
- *Correspondence: Arnaud Chevrollier
| | - Isabelle Maystadt
- Institut de Pathologie et de Génétique, Gosselies, Belgium
- Faculté de Médecine, URPhyM, Université de Namur, Namur, Belgium
- Isabelle Maystadt
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Gerber S, Orssaud C, Kaplan J, Johansson C, Rozet JM. MCAT Mutations Cause Nuclear LHON-like Optic Neuropathy. Genes (Basel) 2021; 12:genes12040521. [PMID: 33918393 PMCID: PMC8067165 DOI: 10.3390/genes12040521] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/18/2021] [Accepted: 03/30/2021] [Indexed: 01/14/2023] Open
Abstract
Pathological variants in the nuclear malonyl-CoA-acyl carrier protein transacylase (MCAT) gene, which encodes a mitochondrial protein involved in fatty-acid biogenesis, have been reported in two siblings from China affected by insidious optic nerve degeneration in childhood, leading to blindness in the first decade of life. After analysing 51 families with negative molecular diagnostic tests, from a cohort of 200 families with hereditary optic neuropathy (HON), we identified two novel MCAT mutations in a female patient who presented with acute, sudden, bilateral, yet asymmetric, central visual loss at the age of 20. This presentation is consistent with a Leber hereditary optic neuropathy (LHON)-like phenotype, whose existence and association with NDUFS2 and DNAJC30 has only recently been described. Our findings reveal a wider phenotypic presentation of MCAT mutations, and a greater genetic heterogeneity of nuclear LHON-like phenotypes. Although MCAT pathological variants are very uncommon, this gene should be investigated in HON patients, irrespective of disease presentation.
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Affiliation(s)
- Sylvie Gerber
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (S.G.); (J.K.)
| | - Christophe Orssaud
- Unité Ophtalmologie, Hôpital Européen Georges-Pompidou (HEGP), and Centre de Référence des Maladies Rares en Ophtalmologie (OPHTARA), Service d’Ophtalmologie, Hôpital Necker–Enfants Malades, 75015 Paris, France;
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (S.G.); (J.K.)
| | - Catrine Johansson
- Botnar Research Centre, Nuffield Orthopaedic Centre, Headington, University of Oxford, Oxford OX3 7LD, UK;
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (S.G.); (J.K.)
- Correspondence:
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Di Nottia M, Verrigni D, Torraco A, Rizza T, Bertini E, Carrozzo R. Mitochondrial Dynamics: Molecular Mechanisms, Related Primary Mitochondrial Disorders and Therapeutic Approaches. Genes (Basel) 2021; 12:247. [PMID: 33578638 PMCID: PMC7916359 DOI: 10.3390/genes12020247] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria do not exist as individual entities in the cell-conversely, they constitute an interconnected community governed by the constant and opposite process of fission and fusion. The mitochondrial fission leads to the formation of smaller mitochondria, promoting the biogenesis of new organelles. On the other hand, following the fusion process, mitochondria appear as longer and interconnected tubules, which enhance the communication with other organelles. Both fission and fusion are carried out by a small number of highly conserved guanosine triphosphatase proteins and their interactors. Disruption of this equilibrium has been associated with several pathological conditions, ranging from cancer to neurodegeneration, and mutations in genes involved in mitochondrial fission and fusion have been reported to be the cause of a subset of neurogenetic disorders.
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Affiliation(s)
| | | | | | | | | | - Rosalba Carrozzo
- Laboratory of Molecular Medicine, Unit of Muscular and Neurodegenerative Disorders, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (M.D.N.); (D.V.); (A.T.); (T.R.); (E.B.)
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Assia Batzir N, Bhagwat PK, Eble TN, Liu P, Eng CM, Elsea SH, Robak LA, Scaglia F, Goldman AM, Dhar SU, Wangler MF. De novo missense variant in the GTPase effector domain (GED) of DNM1L leads to static encephalopathy and seizures. Cold Spring Harb Mol Case Stud 2019; 5:a003673. [PMID: 30850373 PMCID: PMC6549558 DOI: 10.1101/mcs.a003673] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/12/2019] [Indexed: 02/06/2023] Open
Abstract
DNM1L encodes a GTPase of the dynamin superfamily, which plays a crucial role in mitochondrial and peroxisomal fission. Pathogenic variants affecting the middle domain and the GTPase domain of DNM1L have been implicated in encephalopathy because of defective mitochondrial and peroxisomal fission 1 (EMPF1, MIM #614388). Patients show variable phenotypes ranging from severe hypotonia leading to death in the neonatal period to developmental delay/regression, with or without seizures. Familial pathogenic variants in the GTPase domain have also been associated with isolated optic atrophy. We present a 27-yr-old woman with static encephalopathy, a history of seizures, and nystagmus, in whom a novel de novo heterozygous variant was detected in the GTPase effector domain (GED) of DNM1L (c.2072A>G, p.Tyr691Cys). Functional studies in Drosophila demonstrate large, abnormally distributed peroxisomes and mitochondria, an effect very similar to that of middle domain missense alleles observed in pediatric subjects with EMPF1. To our knowledge, not only is this the first report of a disease-causing variant in the GED domain in humans, but this is also the oldest living individual reported with EMPF1. Longitudinal data of this kind helps to expand our knowledge of the natural history of a growing list of DNM1L-related disorders.
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Affiliation(s)
- Nurit Assia Batzir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Pranjali K Bhagwat
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA
| | - Tanya N Eble
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Baylor Genetics, Houston, Texas 77021, USA
| | - Christine M Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Baylor Genetics, Houston, Texas 77021, USA
- Texas Children's Hospital, Houston, Texas 77030, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Baylor Genetics, Houston, Texas 77021, USA
| | - Laurie A Robak
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA
- Texas Children's Hospital, Houston, Texas 77030, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Texas Children's Hospital, Houston, Texas 77030, USA
- BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, ShaTin, New Territories, Hong Kong, SAR
| | - Alica M Goldman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Shweta U Dhar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA
- Texas Children's Hospital, Houston, Texas 77030, USA
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